Try to do Start->regedit.exe
A window will appear, now go to HKEY_CURRENT_USER\Software\Microsoft\Office\Word\AddIns\
If your Add-In was registred correctly, you'll see it there with the parameters
Private Shared ReadOnly _prodId As String = "WordAddinVB4.TaskPaneAddin"
Private Shared ReadOnly _addinFriendlyName As String = "NetOffice Sample Addin in VB"
Private Shared ReadOnly _addinDescription As String = "NetOffice Sample Addin with custom Task Pane"
Hope this will clarify your mind.